navigation
Technical Overview
 

Detector

last modified 18-01-2011 15:09

ESRF/EMBL STAFF ONLY

ID23-2 detector is a 225 mm MarMOSAIC (3072x3072 pixels; pixel size: 73.25 µm).

 

The MarCCD detector is fitted on a translation stage (motor called dtox) carrying from a minimum distance crystal-detector of 60 mm to a maximum of 710 mm.

 225mm MarMOSAIC

The rolling cabinet located in the freeway outside the optic hutch contains the cooling assembly and the power supply.

MarMOSAIC Cabinet

To turn off the detector and if it is only for a short period of time (emergency procedure), one can swith it off and the main switch. The risk of switching off the detector at the main is to loose the vacuum, but that would not be the case if you restart the system not long after having switched off.

 

For the shutdown period, the full and proper procedure is as follow:

  1. Switch off the coolers (two switches in the cabinet).
  2. Wait for the CCDs to reach room temperature (monitor in marccd software, about one and half hours)
  3. Unplug the vacuum valve connector from the back of the detector head and confirm that the vacuum valve has closed (either by hearing the sound - the closing sound is very quiet and difficult to hear, or by checking the vacuum reading in the marccd software - the vacuum starts to come up slightly immediately when the valve closes)
  4. Switch off the vacuum pump using the front panel button
  5. When the pump has stopped (about 10 minutes) switch off the pump power using the switch at the rear
  6. Stop the marccd software
  7. Switch off the power to the detector cabinet (switch at top of rack).

 

For startup:

  1. Turn on the main power on the detector cabinet
  2. Start marCCD software
  3. MarcCCd software: Configure->Detector-> turn off Cooler Power
  4. Turn on the Pfeiffer vacuum pump (switch in the back, then power on in the front).  Also make sure that the primary pump (near the mar controller rack) is on
  5. Re-plug in the vacuum valve connector
  6. Turn on individual cooling units in the rack
  7. Valves on the back of the rack for coolers one and two should show a decrease in pressure
  8. MarcCCD software: Configure->Detector->Cooler Setpoint 25 degrees
  9. Let coolers run for 30 mins-1 hour
  10. MarcCCD software: Configure->Detector->Cooler Setpoint -100

 
For the cooling rejuvination:

 

Stop marccd software.
Start marccd -P  instead. (it can be as well obtained from the marccd software tabs)
Go to "Configure/Detector".
Change the cooler setpoint (not the CCD temp) to 25 (instead of -273).
Click on "Apply" at the bottom of the menu.
Run it like that for 30 minutes or so.
(Explanation: The mosaics have a heater at the point of expansion, which
is where it usually clogs, this turns it on).
Then set the temp back to -273, click Apply, start normal marccd.


Software - hardware communication troubles:
- Try to reboot the control computer with the controller / power supply unit off,
- Check the led near the fiber optic (detector head):
  • if the led is red, they are a communication problem with the PCI card (PC side),
  • if no led on (detector head) but "blinking" on the PCI card, they are a possible problem with the fiber optic.

 
 
European Synchrotron Radiation Facility